Various species of ants pose significant problems for man from both an economic and a health care point of view. For example, leaf-cutting ant species are a problem in Central and South America, where they can defoliate a citrus tree overnight. Consequently, a non-toxic repellent that would prevent leaf-cutting ants from getting into the trees would be of significant value. Also, in the southern United States, fire ants, Solenopsis invicta, are a substantial pest. For example, foraging fire ants are known to destroy young citrus trees, growing crops, and germinating seeds. This has an economic impact on agriculture in infested areas. Telephone companies spend substantial amounts of money each year on treating their electrical equipment to prevent fire ant invasion because fire ants are attracted to electrical fields and can short out electrical equipment. Further, farm equipment can be damaged by large fire ant mounds. Fire ants also present a problem to wildlife, such as with ground nesting birds and animals. Furthermore, Fire ants are known to excavate the soil from under roadways causing damage.
Fire ants also pose a health care problem to the millions of people stung each year--a significant number of which require medical care. Further, fire ant stings are also blamed for human deaths each year. Consequently, there is much interest in controlling these troublesome insects.
This interest has resulted in much research and resources being expended through the years to develop reagents and methods for controlling fire ants. While many useful insecticide formulations have resulted from this research, the problems associated with ants still exist. This is primarily because the relief gained by insecticide use is only temporary owing to the high reproductive capabilities, the efficient foraging behavior, and the ecological adaptability, of ants. While effective for controlling ants in relatively small defined areas, the use of insecticides, because of their toxicity, can create other problems. For example, some insecticides, which are effective for controlling ants, are banned from use because they pose a significant threat to the environment, including birds and animals. Furthermore, there is pressure from environmental groups to stop, or at least substantially reduce, the application of insecticides in general, and to develop non-toxic reagents for controlling insects. One type of reagent which would be of great interest would be a non-toxic reagent which could repel, or keep ants from invading a particular area or object.
Such a reagent would be of great value in preventing leaf-cutting ants from attacking citrus and other agriculturally important trees. It would also be of great value for preventing fire ants from attacking various biological control agents, such as parasitic wasps, which are used to control a host of crop pests, including those which are harmful to cotton. The parasitic wasps are distributed as pupae in small capsules which are dispersed in the area to be controlled. Adult wasps emerge from the capsule within a matter of days. If the capsules are distributed in an area infested with fire ants, the capsules are quickly found by foraging ants which penetrate the capsule and eat the wasp in its pupal stage--thus greatly decreasing the effectiveness of the use of such biological control agents.
Therefore, there is still a substantial need in the art for reagents, particularly non-toxic reagents, which can be used to prevent ants from invading a particular area or object.